feat: add schema registry infos to Kafka binding

[lbroudoux]

Description

As of today, there's no way using 0.2.0 version of Kafka bindings to provide information on whether a Schema Registry was/has to be used to provide/gather schema information for messages published on topics.

However, such information is required to help on two use-cases:

1. Inform API providers to enable schema registry connection and pick the right vendor serdes,
2. Inform API consumers on the same things but also how to bypass if schema registry is unavailable

Use-cases and needed informations have been discussed with @nictownsend and @dalelane. This PR is aggregating validated propositions. The proposition is to add following attributes:

At the server level:

• schemaRegistryUrl - API URL for the Schema Registry used when producing Kafka messages
• schemaRegistryVendor - he vendor of Schema Registry and Kafka serdes library that should be used

At the operation level:

• schemaIdLocation - Tells where the id of schema is stored (e.g. header or payload)
• schemaIdPayloadEncoding - Number of bytes or vendor specific values when schema id is encoded in payload
• schemaLookupStrategy - Freeform string for any naming strategy class to use. Clients should default to the vendor default if not supplied.

Related issue(s)

This PR is related to #40 and #41. It has been initially discussed into PR #55 but finally close due to inactivity.

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[dalelane]

Someone using schemas (and a schema registry) could use that to serialize a message key, the message payload, or both.

Is the assumption here that schema-related bindings settings relate to message payload only?

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity 😴

It will be closed in 120 days if no further activity occurs. To unstale this pull request, add a comment with detailed explanation.

There can be many reasons why some specific pull request has no activity. The most probable cause is lack of time, not lack of interest. AsyncAPI Initiative is a Linux Foundation project not owned by a single for-profit company. It is a community-driven initiative ruled under open governance model.

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Thank you for your patience ❤️

[derberg]

@lbroudoux do you plan to continue with this one?

[lbroudoux]

@lbroudoux do you plan to continue with this one?

Yep. Sorry for the long time no see. Will have more free cycles now 😉

[lbroudoux]

Push a new commit to update to latest spec version.

[dalelane]

👍

[char0n]

@KhudaDad414 @dratasich would you mind looking into this PR again? Thanks!

[dratasich]

Thanks @lbroudoux - I like and appreciate the outcome. From my point of view very useful!

[KhudaDad414]

LGTM! just a small typo.

[dalelane]

nice catch on the typo :)

[char0n]

@derberg this PR is made against master directly. Can we merge this PR?

[fmvilas]

👏 🎉